Good Eats around Oahu Hawaii

If you see a van on the side of the road and a giant grill behind it, STOP. The Huli Huli Chicken is really good!
Waikiki has some really nice, high end restaurants, but kinda touristy.
You've gotta stop at the Polynesian Cultural Center. A tourist attraction but authentic Luau and pig roast.

The shrimp trucks are good but a true locals place is Paalaa Kai Bakery in Waialua. Get the Snow Puffies. You will not be disappointed.

X2 on the Polynesian cultural center. All of the exhibits and shows are great. Also at Waikiki is Dukes. It's good.

Go to Pearl Harbor and take the boat out to the USS Arizona. Visited back in the early 80's. Consider a helicopter tour and possibly check into an island hopping pass at the airport. The pass allows you to fly to any island for a set price without reservations. When Aloha Airlines was doing this years ago, you arrived at the airport, the attendant would point to a gate and tell you what plane was about to leave for what island. Pretty cool. I hate to say this, but to really experience Hawaii, you need to get off of Oahu. I love Kawaii and would recommend a hike into the Na Pali rain forest. This is where Jurassic Park was filmed. Happy trails.
http://www.kauaiexplorer.com/hiking_kauai/kalalau_hike.php

Agree with previous, each island is different. Just got back from a week on Maui and a week on Big Island. Other trips have been to Kauai, Oahu, and Maui. Kauai is my favorite with Big Island next... Lots of good food around, I like Huli Huli chicken, you gotta try some Spam Musubi available at any convenience store or corner shop. Drink lots of POG, (passion, orange, Guava juice). Pearl Harbor is a must stop. A good Luau is a must, low (literally) and slow pork done kinda bbq pit style.